Typically, 3D stereo image includes a reference image and a 3D supplement image having various forms and the two images are respectively converted into left and right images. 3D effect is given by playing these two images on 3D display. Here, the 3D supplement image may be a half of vertical (horizontal) right image, a full right image, another half of vertical (horizontal) image (or a quarter image), or a depth/disparity image. For example, when the 3D supplement image is the half of vertical (horizontal) right image, the reference image and the 3D supplement image are respectively converted to an image having only 3D supplement image odd (even) line data and an image having only even (odd) line data. Then, left and right field images are played to the same place in a scene on 3D display at a time.
In 3D digital broadcasting which developed to be compatible with typical 2D digital broadcasting, the reference image and the 3D supplement image are encoded by an additional encoder and then transmitted. A receiver also needs an additional decoder for these two images. Therefore, for this kind of 3D digital broadcasting, conventional digital broadcasting standard needs to be upgraded and a little complex system needs to be developed.